Hollow rope conductor for overhead transmission lines



, A. SCHALKAU HOLLOW ROPE CONDUCTOR FOR OVERHEAD TRANSMISSION LINES Aug Filed June 22, 1926 Patented Aug. 6, 1929.

UNITED STATES PATENT oFFica LRTUR SCEALKAU, OF BERLIN -CHA.RLOTTENBURG, GERMANY, ASSIGNOR T SIEMENS- SCHUCKERTWERKR GESELLSCHLFT MIT BESCHRANKTER HAFTUNG, OF SIEIENS- 1 STADT, NEAR BERLIN, GERMANY, A CORPORATION OF GERMANY.

HOLLOW ROPE CONDUCTOR FOR OVERHEAD TRANSMISSION LINES.

Application fled June 28, 1928, serial No.

My invention relates to hollow rope conductors for overhead transmission lines.

In hollow .or tubular rope conductors which consist of two or more layers of line 8 wires stranded over a supporting member or element, a considerab sion and compression stress is developed durin the laying as welL as in service, in- 8151111151 as the longitudinal ressure caused 10 by the weight of the rope orces the wires towards the interior and thus against the supporting element. At the laces of the inner layer of wires where e wires rest with comparatively small surfaces upon the support, a notching action is thus set up,

which when the rope is repeatedly bent freuently leads to a rupture of the rope at t ose places. A

The object of m invention is to eliminate this drawback. attain this end in view by making the cross-sectional area of the wires of the inner la er larger than the cross-sectional area 0 the wires of the outer layer or layers. In the inner layer of wires of large cross-section an arch is provided in this manner which ,su port's itself and to which the supporting e ement only serves as idle or false framing. The wires of the inner layer are not forced against the su porting member by the longitudinal but-take up the pressure mutually in the manner of the stones in an arch so that any notchi of the wires by the supporting element is entirel eliminated. Preferably the wires of t e inner layer are given at least double the crosssection of the wires in the outer layer.

In order to impart to the wires a good mutual supporting capacity, the wires of the inner layer are according to my invention made of greater thickness in a radial direction than the wires of the outer layer.

I Preferabl the ratio of the thickness of the wires of the inner layer to that of the outer layer is made at least 1.521. An inner layer of wires thus designed is entirelyselfsupporting so that the rope completely maintains its round ,form essential or the avoidance of corona efl'ects and does not lo become distorted like the hitherto employed e combined ten- 117,889, and in Germany February 4, 1928.

hollow rope constructions of equal wire thickness in the inner and outer la' er, so that the sha e of the supporting mem r becomes clear y visible upon. the surface of the ro g In t e drawing aflixed hereto a cross-seetion through the improved hollow or tubular conductor is shown.

Referrin to the single figure of the drawing, 1 is t e twisted strip serving as supporting member, 2 the wires of the inner .layer which possess double the crox-sectlonal area as the wires 3 of the outer layer and the radial thickness of which amounts to 1.5 times the. thickness of the outer wires. For the purpose of ensuring agood mutual support all the wires are designed as sec- 4 torial elements of a cylinder. It will be understood that more than two layers of wires may be employed. Various modifications and ch es may be made without departing from t e irit and the scope of my invention, and def sire, therefore, that only such limitations shall be placed thereon as are imposed by the prior art.

I claim as my invention.

1. A hollow rope conductor for electric overhead transmission lines, comprising an internal shape defining member and a plurality of layers of sector-shaped line wires stranded ove'r said internal member, the cross-sectional area of the wires in the inner layer being larger than the cross-sectional area of the wires in the outer layers, to permit the inner layer to form a strong archlike sup rt for the outer layers.

2A ollow rope conductor for electric overhead transmission lines, comprising an internal shape defining member and a'plurality of layersof sector-shaped-line wires v internal shape-defining member and'a plu- 'rality of layers of sector-shaped line wires 10 permit'the inner layer to form a strongarch-like support forthe outer layers.

4:. A hollow rope conductor for electric overhead transmission lines, comprising an internal shape-defining member and a plurality of layers. of sector-shaped line wires stranded over said internal member thecro'ss-sectional area of the wires in the inner layer being at least double the size of the cross-sectional area of the wires in theouter layer and the thickness ofthe wires of the 20 inner layer to that of the wires of theouter layers being at least in the ratio of 1.5: 1, to permit the inner layer to form a'strfong arch-like support for the outer layers.

ture.

ABTUR SCHAZLKIAUQ i In testimony whereof I aflix my -signa-. 5 

